The overall goal in Phase I is to develop a method to efficiently cryopreserve embryos from the BB/Wor rat strains. Funding is requested to determine which established technique (slow equilibration, two step equilibration, or vitrification) is most suited to obtain cryopreserved embryos. Once a method has been selected, we will cryopreserve circa 20 years of genetic inbreeding and concurrently make available new reagents for the study of human diabetic embryopathy. PROPOSED COMMERCIAL APPLICATION: This proposal will result in an animal model system for the study of diabetic embryopathy. This proposal will also lower the costs associated with the commercial production of BB/Wor rats.